A significant body of research indicates that preadolescent children who are raised by substance-abusing parents often manifest substantial emotional, behavioral, and social problems. Despite this, most custodial parents who enter treatment for substance abuse are very reluctant to allow their children to be involved in any type of psychosocial intervention, regardless of whether it be individual treatment for the child or as part of family therapy. Thus, interventions for substance-abusing parents that do not involve their children, which nonetheless serve to improve the family environment as a whole, may actually hold the most potential for improving the psychosocial adjustment of children who live in these homes. Moreover, such interventions may help prevent the poor outcomes often observed in these high risk children as they enter adolescence and early adulthood. Results of a recent study conducted by our investigative team indicate children whose substance-abusing fathers and nonsubstance-abusing mothers participated in Behavioral Couples Therapy (BCT) displayed higher psychosocial adjustment at posttreatment and during an extended posttreatment follow-up period than children whose substance-abusing fathers participated in treatment-as-usual or whose parents participated in a couples-based attention control treatment. These encouraging findings suggest BCT has significant effects on the family that extend beyond the couple to their children, even though (a) the children themselves were not actively involved in treatment, (b) parent skills training was not a component of the treatment, and (c) parenting issues were not discussed during the course of BCT. It is plausible, however, that the effects of BCT for parents on their on children may be enhanced further if parent training is integrated into the couples therapy intervention. Thus, the purpose of the Stage II investigation is to conduct a longitudinal randomized clinical trial to examine the clinical effects of a new, hybrid treatment, Parent Skills Training plus BCT (PSBCT) compared to (a) standard BCT; (b) Parent Training only (PT); and (c) Treatment-As-Usual (TAU). More specifically, married or cohabiting substance-abusing fathers and nonsubstance-abusing mothers (N = 216 couples) entering outpatient treatment who live with and parent one or more preadolescent children will be recruited for the study. Participants in the treatment conditions will be compared in terms of children's adjustment, fathers' substance use, and family and relationship functioning. Extensive cost, cost-benefit, and cost-effectiveness comparisons will also be conducted. As a new treatment targeted at substance-abusing patients and their children, PSBCT could potentially have broad and prolonged effects that extend beyond the patients seeking treatment for substance abuse to the children under their care.